1. Field of the Invention
The invention relates to extraction cleaning machines incorporating agitation brushes. In one of its aspects, the invention relates to an extraction cleaning machine incorporating a multi-row agitation brush. In another of its aspects, the invention relates to extraction cleaning machines incorporating a twist-wire agitation brush. In yet another of its aspects, the invention relates to extraction cleaning machines incorporating an agitation brush dampening mechanism. In yet another of its aspects, the invention relates to an extraction cleaning machines incorporating an agitation brush that applies a predetermined force to a carpet.
2. Description of Related Art
Extraction cleaning machines are used for removing dirt from surfaces such as carpeting, upholstery, drapes and the like. Known extraction cleaning machines can be in the form of a canister-type unit as disclosed in U.S. Pat. No. 5,237,720 to Blase et al.; an upright unit as disclosed in U.S. Pat. No. 6,134,744 to Kasen et al. and U.S. Pat. No. 6,167,587 to Kasper et al.; and a hand-held unit as disclosed in U.S. Pat. No. 5,367,740 to McCray.
Vacuum cleaning machines are also used for removing dirt from surfaces. Vacuum cleaning machines have rotating brushes to agitate the surface, thus enhancing cleaning effectiveness. Brushes can be in the form of multiple rows of bristles as disclosed in U.S. Pat. No. 2,659,921 to Osborn, and twist-wire type bristles in U.S. Pat. No. 1,205,162 to Clements.